Done
http://bugs.mysql.com/30269

Please, report a bug about this waste of memory in the query cache.

We’re just trying to keep things usable for people which are still stuck with MySQL Enterprise version.

Though I hope you’ve seen my post regarding potentially high overhead of SHOW PROFILE patch even when it is disabled
if there is huge query volume.

mysql> SELECT id FROM xp.test1 WHERE id> 1;
+——+
| id |
+——+
| 5 |
+——+
1 row in set (0.00 sec)

mysql> show profile;
+——————————–+———-+
| Status | Duration |
+——————————–+———-+
| (initialization) | 0.000005 |
| checking query cache for query | 0.000049 |
| checking permissions | 0.00001 |
| Opening tables | 0.000011 |
| System lock | 0.000007 |
| Table lock | 0.000017 |
| init | 0.000021 |
| optimizing | 0.000009 |
| statistics | 0.000028 |
| preparing | 0.000013 |
| executing | 0.000005 |
| Sending data | 0.000036 |
| end | 0.000008 |
| query end | 0.000005 |
| storing result in query cache | 0.000005 |
| freeing items | 0.000012 |
| closing tables | 0.000007 |
| logging slow query | 0.000224 |
+——————————–+———-+
18 rows in set (0.00 sec)

mysql> SELECT id FROM xp.test1 WHERE id> 1;
+——+
| id |
+——+
| 5 |
+——+
1 row in set (0.00 sec)

mysql> show profile;
+——————————–+———-+
| Status | Duration |
+——————————–+———-+
| (initialization) | 0.000005 |
| checking query cache for query | 0.000008 |
| checking privileges on cached | 0.000006 |
| checking permissions | 0.000051 |
| Opening tables | 0.000012 |
| System lock | 0.000006 |
| Table lock | 0.00001 |
| init | 0.000021 |
| optimizing | 0.00001 |
| statistics | 0.000028 |
| preparing | 0.000012 |
| executing | 0.000005 |
| Sending data | 0.000024 |
| end | 0.000007 |
| query end | 0.000004 |
| freeing items | 0.000012 |
| closing tables | 0.000007 |
| logging slow query | 0.000004 |
+——————————–+———-+
18 rows in set (0.00 sec)